/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.module.extension.internal.loader.enricher;

import static java.lang.Thread.currentThread;
import static org.mule.runtime.api.meta.model.display.LayoutModel.builderFrom;
import static org.mule.runtime.module.extension.internal.util.IntrospectionUtils.getAnnotatedElement;
import org.mule.metadata.api.ClassTypeLoader;
import org.mule.runtime.api.meta.model.declaration.fluent.BaseDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.ComponentDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.ExtensionDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.OperationDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.ParameterDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.ParameterDeclarer;
import org.mule.runtime.api.meta.model.declaration.fluent.ParameterGroupDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.SourceDeclaration;
import org.mule.runtime.api.meta.model.declaration.fluent.TypedDeclaration;
import org.mule.runtime.core.internal.metadata.DefaultMetadataResolverFactory;
import org.mule.runtime.core.internal.metadata.NullMetadataResolverFactory;
import org.mule.runtime.extension.api.annotation.metadata.MetadataKeyId;
import org.mule.runtime.extension.api.annotation.metadata.MetadataKeyPart;
import org.mule.runtime.extension.api.annotation.metadata.MetadataScope;
import org.mule.runtime.extension.api.annotation.param.Query;
import org.mule.runtime.extension.api.declaration.fluent.util.IdempotentDeclarationWalker;
import org.mule.runtime.extension.api.declaration.type.ExtensionsTypeLoaderFactory;
import org.mule.runtime.extension.api.exception.IllegalParameterModelDefinitionException;
import org.mule.runtime.extension.api.loader.DeclarationEnricher;
import org.mule.runtime.extension.api.loader.ExtensionLoadingContext;
import org.mule.runtime.extension.api.metadata.MetadataResolverFactory;
import org.mule.runtime.module.extension.internal.loader.java.property.ImplementingMethodModelProperty;
import org.mule.runtime.module.extension.internal.loader.java.property.ImplementingParameterModelProperty;
import org.mule.runtime.module.extension.internal.loader.java.property.ImplementingTypeModelProperty;
import org.mule.runtime.extension.internal.property.MetadataKeyIdModelProperty;
import org.mule.runtime.extension.internal.property.MetadataKeyPartModelProperty;
import org.mule.runtime.module.extension.internal.loader.java.property.MetadataResolverFactoryModelProperty;
import org.mule.runtime.module.extension.internal.loader.java.property.ParameterGroupModelProperty;
import org.mule.runtime.module.extension.internal.loader.java.property.QueryParameterModelProperty;
import org.mule.runtime.module.extension.internal.metadata.MetadataScopeAdapter;
import org.mule.runtime.module.extension.internal.metadata.QueryMetadataResolverFactory;

import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.Optional;
import java.util.Set;

/**
 * {@link DeclarationEnricher} implementation that walks through a {@link ExtensionDeclaration} and looks for components (Operations and
 * Message sources) annotated with {@link MetadataScope} or {@link Query}. If a custom metadata scope is used, the component will
 * be considered of dynamic type.
 *
 * @since 4.0
 */
public class DynamicMetadataDeclarationEnricher implements DeclarationEnricher {

  @Override
  public void enrich(ExtensionLoadingContext extensionLoadingContext) {
    new EnricherDelegate().enrich(extensionLoadingContext);
  }

  private class EnricherDelegate extends AbstractAnnotatedDeclarationEnricher {

    private Class<?> extensionType;
    private ClassTypeLoader typeLoader;

    @Override
    public void enrich(ExtensionLoadingContext extensionLoadingContext) {
      Optional<ImplementingTypeModelProperty> implementingType =
          extractImplementingTypeProperty(extensionLoadingContext.getExtensionDeclarer().getDeclaration());
      if (implementingType.isPresent()) {
        extensionType = implementingType.get().getType();
        typeLoader = ExtensionsTypeLoaderFactory.getDefault().createTypeLoader(currentThread().getContextClassLoader());

        new IdempotentDeclarationWalker() {

          @Override
          public void onSource(SourceDeclaration declaration) {
            enrichSourceMetadata(declaration);
          }

          @Override
          public void onOperation(OperationDeclaration declaration) {
            enrichOperationMetadata(declaration);
          }

          @Override
          protected void onParameter(ParameterGroupDeclaration parameterGroup, ParameterDeclaration declaration) {
            enrichParameter(declaration);
          }
        }.walk(extensionLoadingContext.getExtensionDeclarer().getDeclaration());
      }
    }

    private void enrichParameter(ParameterDeclaration declaration) {
      Optional<AnnotatedElement> annotatedElement = getAnnotatedElement(declaration);

      if (annotatedElement.isPresent()) {
        parseMetadataAnnotations(annotatedElement.get(), declaration);
      }
    }

    private void enrichSourceMetadata(SourceDeclaration declaration) {
      declaration.getModelProperty(ImplementingTypeModelProperty.class)
          .ifPresent(prop -> {
            final Class<?> sourceType = prop.getType();
            MetadataScopeAdapter metadataScope = new MetadataScopeAdapter(extensionType, sourceType);
            declareMetadataResolverFactory(declaration, metadataScope);
          });
    }

    private void enrichOperationMetadata(OperationDeclaration declaration) {
      declaration.getModelProperty(ImplementingMethodModelProperty.class)
          .ifPresent(prop -> {
            final Method method = prop.getMethod();

            if (method.isAnnotationPresent(Query.class)) {
              enrichWithDsql(declaration, method);
            } else {
              MetadataScopeAdapter metadataScope = new MetadataScopeAdapter(extensionType, method, declaration);
              declareMetadataResolverFactory(declaration, metadataScope);
            }
          });
    }

    private void declareMetadataResolverFactory(ComponentDeclaration<? extends ComponentDeclaration> declaration,
                                                MetadataScopeAdapter metadataScope) {
      MetadataResolverFactory metadataResolverFactory = getMetadataResolverFactory(metadataScope);
      declaration.addModelProperty(new MetadataResolverFactoryModelProperty(metadataResolverFactory));
      declareMetadataKeyId(declaration);
      declareOutputResolvers(declaration, metadataScope);
      declareInputResolvers(declaration, metadataScope);
    }

    private void enrichWithDsql(OperationDeclaration declaration, Method method) {
      Query query = method.getAnnotation(Query.class);
      declaration.addModelProperty(new MetadataResolverFactoryModelProperty(
                                                                            new QueryMetadataResolverFactory(query
                                                                                .nativeOutputResolver(), query
                                                                                    .entityResolver())));
      addQueryModelProperties(declaration, query);
      declareDynamicType(declaration.getOutput());
      declareMetadataKeyId(declaration);
    }


    private void addQueryModelProperties(OperationDeclaration declaration, Query query) {
      ParameterDeclaration parameterDeclaration = declaration.getAllParameters()
          .stream()
          .filter(p -> p.getModelProperty(ImplementingParameterModelProperty.class).isPresent())
          .filter(p -> p.getModelProperty(ImplementingParameterModelProperty.class).get()
              .getParameter().isAnnotationPresent(MetadataKeyId.class))
          .findFirst()
          .orElseThrow(() -> new IllegalParameterModelDefinitionException(
                                                                          "Query operation must have a parameter annotated with @MetadataKeyId"));

      parameterDeclaration.addModelProperty(new QueryParameterModelProperty(query.translator()));
      parameterDeclaration.setLayoutModel(builderFrom(parameterDeclaration.getLayoutModel()).asQuery().build());
    }

    private MetadataResolverFactory getMetadataResolverFactory(MetadataScopeAdapter scope) {

      return scope.isCustomScope() ? new DefaultMetadataResolverFactory(scope.getKeysResolver(), scope.getInputResolvers(),
                                                                        scope.getOutputResolver(), scope.getAttributesResolver())
          : new NullMetadataResolverFactory();

    }

    private void declareInputResolvers(ComponentDeclaration<?> declaration, MetadataScopeAdapter metadataScope) {
      if (metadataScope.hasInputResolvers()) {
        Set<String> dynamicParameters = metadataScope.getInputResolvers().keySet();
        declaration.getAllParameters().stream()
            .filter(p -> dynamicParameters.contains(p.getName()))
            .forEach(this::declareDynamicType);
      }
    }

    private void declareOutputResolvers(ComponentDeclaration<?> declaration, MetadataScopeAdapter metadataScope) {
      if (metadataScope.hasOutputResolver()) {
        declareDynamicType(declaration.getOutput());
      }

      if (metadataScope.hasAttributesResolver()) {
        declareDynamicType(declaration.getOutputAttributes());
      }
    }

    private void declareDynamicType(TypedDeclaration component) {
      component.setType(component.getType(), true);
    }

    private void declareMetadataKeyId(ComponentDeclaration<? extends ComponentDeclaration> component) {
      getMetadataKeyModelProperty(component).ifPresent(property -> component.addModelProperty(property));
    }

    private Optional<MetadataKeyIdModelProperty> getMetadataKeyModelProperty(
                                                                             ComponentDeclaration<? extends ComponentDeclaration> component) {
      Optional<MetadataKeyIdModelProperty> keyId = findMetadataKeyIdInGroups(component);
      return keyId.isPresent() ? keyId : findMetadataKeyIdInParameters(component);
    }

    private Optional<MetadataKeyIdModelProperty> findMetadataKeyIdInGroups(
                                                                           ComponentDeclaration<? extends ComponentDeclaration> component) {
      return component.getParameterGroups().stream()
          .map(group -> group.getModelProperty(ParameterGroupModelProperty.class).orElse(null))
          .filter(group -> group != null)
          .filter(group -> group.getDescriptor().getContainer().getAnnotation(MetadataKeyId.class) != null)
          .map(group -> new MetadataKeyIdModelProperty(typeLoader.load(group.getDescriptor().getType().getDeclaringClass()),
                                                       group.getDescriptor().getName()))
          .findFirst();
    }

    private Optional<MetadataKeyIdModelProperty> findMetadataKeyIdInParameters(
                                                                               ComponentDeclaration<? extends ComponentDeclaration> component) {
      return component.getParameterGroups().stream()
          .flatMap(g -> g.getParameters().stream())
          .filter(p -> getAnnotatedElement(p).map(element -> element.isAnnotationPresent(MetadataKeyId.class)).orElse(false))
          .map(p -> new MetadataKeyIdModelProperty(p.getType(), p.getName()))
          .findFirst();
    }

    /**
     * Enriches the {@link ParameterDeclarer} with a {@link MetadataKeyPartModelProperty}
     * if the parsedParameter is annotated either as {@link MetadataKeyId} or {@link MetadataKeyPart}
     *
     * @param element         the method annotated parameter parsed
     * @param baseDeclaration the {@link ParameterDeclarer} associated to the parsed parameter
     */
    private void parseMetadataAnnotations(AnnotatedElement element, BaseDeclaration baseDeclaration) {
      if (element.isAnnotationPresent(MetadataKeyId.class)) {
        baseDeclaration.addModelProperty(new MetadataKeyPartModelProperty(1));
      }

      if (element.isAnnotationPresent(MetadataKeyPart.class)) {
        MetadataKeyPart metadataKeyPart = element.getAnnotation(MetadataKeyPart.class);
        baseDeclaration.addModelProperty(new MetadataKeyPartModelProperty(metadataKeyPart.order()));
      }
    }
  }
}
